Earlier, Russian President Vladimir Putin had said that the two countries should avoid a diplomatic showdown over the issue. But he refused to back off his refusal to turn over Snowden to the US.

"We agree with President Putin that we do not want this issue to negatively impact our bilateral relations. While we do not have an extradition treaty with Russia, there is nonetheless a clear legal basis to expel Snowden, based on the status of his travel documents and the pending charges against him," Caitlin Hayden, spokesperson of the National Security Council, White House said on Tuesday.

"Accordingly, we are asking the Russian Government to take action to expel Snowden without delay and to build upon the strong law enforcement cooperation we have had, particularly since the Boston Marathon bombing," Hayden said.

Snowden remained for a third day in the transit zone of Sheremetyevo Airport, and Putin said he was out of Moscow's reach since he had not passed through immigration and was, technically, not in Russian territory.

Meanwhile, the State Department said that it does not want to raise the level of confrontation and said that it wants to get it resolved through routine law enforcement channels.